File:Unipolar symmetrical electrostatic generators for energy harvesting.webm

English: Demo proposal fo the 2017 IEEE ISCAS.

Example of the operation of a 3D-printed electrostatic generator, with two complementary variable capacitors made with conductive ABS plastic and diode-capacitor symmetrical voltage multipliers. The generator is demonstrated with three kinds of 2-phase voltage multipliers, that connected to the variable capacitors form unstable circuits where the voltages rise exponentially. The generator's output is fed to a DC/DC converter, and the output at low voltage is used to power a wireless transceiver controlled by a PIC. The system consumes just a few tens of uW. The variable capacitor assembly has a structure compatible with MEMS fabrication. Originally it was built with the moveable section suspended by 3D-printed springs, but these proved too fragile and were replaced by metal foil (copper) springs. The capacitances vary between 90 pF and 210 pF. The device resonates mechanically at 18 Hz, vibrated by a solenoid interacting with a magnet fixed to the structure. A controller built with CMOS standard gates discharges the device through a buck DC/DC converter at ~250 V, producing 5 V and 3.3 V. The 5 V output can be used to power the controller itself. The 3.3 V output is stored in a capacitor and used to power the wireless system briefly (~40 ms) at each 128 operations of the DC/DC converter. The wireless system in the video just turns on and off a LED in the receiver, but more complex operations with bidirectional communication are possible too. In the final version for the demo, the assembly and the instruments will be more compact.

Variable capacitors generate energy, because it's necessary to apply a force to separate charged plates. A practical generator can be built in many ways. Some examples are in http://www.coe.ufrj.br/~acmq/bennetd.html , http://www.coe.ufrj.br/~acmq/tubular/ , http://www.coe.ufrj.br/~acmq/wilsonel/ . This generator is similar to the one in the last link, with a different construction for the variable capacitors. Some detailed papers about them are in http://www.coe.ufrj.br/~acmq/papers/papers.html

By Dr. Antônio Carlos M. de Queiroz (in memoriam).

https://www.youtube.com/user/acmdq2007/videos https://acmq-326823.web.app/ https://www.flickr.com/photos/194095199@N08/

Thousands of documents collected by Dr. Antonio Queiroz about Electricity and Electrostatic Machines: https://drive.google.com/drive/folders/1kkG_YwNKi0tMsoun2BSVd5vTxmtlfpw7?usp=sharing